Methods and compositions for treating and preventing disease associated with alpha-v beta-8 integrin

ABSTRACT

Antibodies (e.g., isolated antibodies) that specifically bind to human integrin β8 and inhibit adhesion of latency associated peptide (LAP) to αvβ8 are provided. In some embodiments, the antibody cross-reacts with mouse integrin β8. In some embodiments, the antibody blocks TGFJ3 activation. In some embodiments, the antibody antagonizes binding of LAP to αβ8 with an IC50 below 5 nM.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Appl. No. 61/807,195, filed Apr. 1, 2013, the disclosure of which is incorporated herein in its entirety.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

This invention was made with government support under grant nos. R37 HL053949 and U19 AI077439 awarded by the National Institutes of Health. The government has certain rights in the invention.

REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED AS AN ASCII TEXT FILE

The Sequence Listing written in file 81906-904963_ST25.TXT, created on Mar. 27, 2014, 46,241 bytes, machine format IBM-PC, MS-Windows operating system, is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Members of the integrin family recognize a variety of spatially-restricted extracellular ligands. Classically, ligation of integrins activates cytoplasmic signals in the integrin-expressing cell and contributes to cell adhesion, migration, proliferation and survival. At least two members of this family, αvβ6 and αvβ8, perform an additional function, activation of latent complexes of transforming growth factor β. In effect, this process allows integrins on one cell to activate signals on adjacent (in the case of αvβ6) or nearby cells (in the case of αvβ8). Integrin-mediated TGFβ activation has been shown to play roles in, for example, modulating tissue fibrosis, acute lung injury and pulmonary emphysema.

BRIEF SUMMARY OF THE INVENTION

Antibodies (e.g., isolated antibodies) that specifically bind to human integrin β8 and inhibit adhesion of latency associated peptide (LAP) to αvβ8 are provided. In some embodiments, the antibody cross-reacts with mouse integrin β8. In some embodiments, the antibody blocks TGFβ activation. In some embodiments, the antibody antagonizes binding of LAP to αvβ8 with an IC₅₀ below 5 nM.

In some embodiments, the antibody competes for binding with an antibody selected from the group consisting of ADWA-2 (ADWA-2, ADWA-2-1 and ADWA-2-2), ADWA-8 (ADWA-8, ADWA-8-1, ADWA-8-2, ADWA-8-3), ADWA-10, ADWA-11, ADWA-13 (ADWA-13, ADWA-13-1, ADWA-13-2), ADWA-15, ADWA-16, ADWA-25, and ADWA-20.

In some embodiments, the antibody comprises the complementarity determining regions (CDR1, CDR2, and CDR3) of the heavy and light chain variable regions of an antibody selected from ADWA-2 (ADWA-2, ADWA-2-1 and ADWA-2-2), ADWA-8 (ADWA-8, ADWA-8-1, ADWA-8-2, ADWA-8-3), ADWA-10, ADWA-11, ADWA-13 (ADWA-13, ADWA-13-1, ADWA-13-2), ADWA-15, ADWA-16, ADWA-25, and ADWA-20. In some embodiments, the antibody comprises the Chothia-determined CDR1, CDR2, and CDR3 of the heavy and light chain variable regions of an antibody selected from ADWA-2 (ADWA-2, ADWA-2-1 and ADWA-2-2), ADWA-8 (ADWA-8, ADWA-8-1, ADWA-8-2, ADWA-8-3), ADWA-10, ADWA-11, ADWA-13 (ADWA-13, ADWA-13-1, ADWA-13-2), ADWA-15, ADWA-16, ADWA-25, and ADWA-20. In some embodiments, antibody comprises the Kabat-determined CDR1, CDR2, and CDR3 of the heavy and light chain variable regions of an antibody selected from ADWA-2 (ADWA-2, ADWA-2-1 and ADWA-2-2), ADWA-8 (ADWA-8, ADWA-8-1, ADWA-8-2, ADWA-8-3), ADWA-10, ADWA-11, ADWA-13 (ADWA-13, ADWA-13-1, ADWA-13-2), ADWA-15, ADWA-16, ADWA-25, and ADWA-20.

In some embodiments, the antibody comprises the heavy and light chain variable regions of an antibody selected from ADWA-2 (ADWA-2, ADWA-2-1 and ADWA-2-2), ADWA-8 (ADWA-8, ADWA-8-1, ADWA-8-2, ADWA-8-3), ADWA-10, ADWA-11, ADWA-13 (ADWA-13, ADWA-13-1, ADWA-13-2), ADWA-15, ADWA-16, ADWA-25, and ADWA-20.

In some embodiments, the antibody comprises the heavy chain CDRs (Chothia or Kabat) shown in SEQ ID NOs:23-25, and the light chain CDRs shown in SEQ ID NOs:46-48. In some embodiments, the antibody comprises the heavy chain CDRs (Chothia or Kabat) shown in SEQ ID NOs:23, 26, and 25, and the light chain CDRs shown in SEQ ID NOs:46-48. In some embodiments, the antibody comprises the heavy chain CDRs (Chothia or Kabat) shown in SEQ ID NOs:27-29, and the light chain CDRs shown in SEQ ID NOs:46, 49, and 50. In some embodiments, the antibody comprises the heavy chain CDRs (Chothia or Kabat) shown in SEQ ID NOs:30-32, and the light chain CDRs shown in SEQ ID NOs:51-53. In some embodiments, the antibody comprises the heavy chain CDRs (Chothia or Kabat) shown in SEQ ID NOs:33-35, and the light chain CDRs shown in SEQ ID NOs:54-56. In some embodiments, the antibody comprises the heavy chain CDRs (Chothia or Kabat) shown in SEQ ID NOs:36-38, and the light chain CDRs shown in SEQ ID NOs:57-59. In some embodiments, the antibody comprises the heavy chain CDRs (Chothia or Kabat) shown in SEQ ID NOs:36, 39, and 38, and the light chain CDRs shown in SEQ ID NOs:57-59. In some embodiments, the antibody comprises the heavy chain CDRs (Chothia or Kabat) shown in SEQ ID NOs:40-42, and the light chain CDRs shown in SEQ ID NOs:60-62. In some embodiments, the antibody comprises the heavy chain CDRs (Chothia or Kabat) shown in SEQ ID NOs:43-45, and the light chain CDRs shown in SEQ ID NOs:63-65.

Any of the antibodies described herein can include one or more human framework region (e.g., 1, 2, 3, or 4 FRs). In some embodiments, the one or more human framework region includes at least one back mutation. Pharmaceutical compositions comprising any of the antibodies described herein are also provided.

Isolated nucleic acid encoding any of the antibodies described herein are also provided (e.g., SEQ ID NOs:66-87, and conservative variants thereof). Expression vectors comprising the nucleic acid are also provided. Isolated host cells comprising the vectors are also provided.

Also provided are methods of reducing TGFβ activation in a human in need thereof. In some embodiments, the methods comprise administering a sufficient amount of the antibody as described herein to the human, thereby reducing TGFβ activation in the human. In some embodiments, the human has a disease selected from the group consisting of asthma, multiple sclerosis or acute lung injury and at least one symptom of the disease is ameliorated by the reduced TGFβ activation. In some embodiments, the human has a disease selected from the group consisting of rheumatoid arthritis, psoriasis and chronic obstructive pulmonary disease and at least one symptom of the disease is ameliorated by the reduced TGFβ activation.

Also provided is a method of detecting the presence or quantity of integrin β8 in a biological sample. In some embodiments, the method comprises contacting the biological sample with the antibody as described herein and detecting the presence, absence, or quantity of the antibody specifically bound to β8 in the sample. In some embodiments, the antibody is linked to a detectable label, wherein the label is fluorescent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides flow cytometry plots of primary astrocytes bound by antibodies as described in Example 1.

FIG. 2 shows data from LAP adhesion blocking experiments as described in Example 1.

FIG. 3 shows data for TGF13 activation as described in Example 1.

FIG. 4 shows data for ADWA-2 blocking of TGFβ activation at the indicated concentrations. Controls shown on the right include the 1D11 antibody specific for TGFβ, and no antibody.

FIG. 5 shows data for ADWA-11 blocking of TGFβ activation at the indicated concentrations. Controls shown on the right include the 1D11 antibody specific for TGFβ, and no antibody.

FIG. 6 shows data for ADWA-13 blocking of TGFβ activation at the indicated concentrations. Controls shown on the right include the 1D11 antibody specific for TGFβ, and no antibody.

FIG. 7 shows data for ADWA-15 blocking of TGFβ activation at the indicated concentrations. Controls shown on the right include the 1D11 antibody specific for TGFβ, and no antibody.

FIG. 8 shows data for ADWA-16 blocking of TGFβ activation at the indicated concentrations. Controls shown on the right include the 1D11 antibody specific for TGFβ, and no antibody.

FIG. 9 shows data for ADWA-11 blocking of LAP adhesion. LAP concentrations for each sample are, from left to right, 3 ug/ml, 1 ug/ml, and 0.3 ug/ml. Controls are no antibody (left) and 3G9 antibody specific for β6 (middle).

FIG. 10 shows data for ADWA-2 (left) and ADWA-16 (right) blocking of LAP adhesion at the indicated concentrations. LAP was contacted with cells at 1 ug/ml.

FIG. 11 shows data for ADWA-11 blocking of LAP adhesion. LAP concentrations for each sample are shown. Controls are no antibody (left) and 3G9 antibody specific for β6 (middle) for each concentration of LAP.

FIG. 12 shows data for ADWA-2, ADWA-8, ADWA-10, ADWA-11, and ADWA-13 blocking of LAP adhesion at various antibody concentrations. LAP was contacted with cells at 1 ug/ml. For each antibody, left to right, concentration was 10 ug/ml, 1 ug/ml, and 0.1 ug/ml. Results for control 3G9 antibody are shown on the right.

FIG. 13 shows data for ADWA-15, ADWA-16, ADWA-20, and ADWA-25 blocking of LAP adhesion at various antibody concentrations. LAP was contacted with cells at 1 ug/ml. For each antibody, left to right, concentration was 10 ug/ml, 1 ug/ml, and 0.1 ug/ml. Results for control 3G9 antibody are shown on the right.

DETAILED DESCRIPTION OF THE INVENTION I. Introduction

Various antibodies that bind to human integrin β8 and that inhibit adhesion of latency associated peptide (LAP) are provided.

II. Definitions

An “antagonist” refers to an agent that binds to an integrin (e.g., αvβ8) and partially or totally blocks stimulation, decreases, prevents, delays activation, inactivates, desensitizes, or down regulates the activity of the integrin.

The terms “identical” or percent “identity,” in the context of two or more nucleic acids or polypeptide sequences, refer to two or more sequences or subsequences that are the same or have a specified percentage of amino acid residues or nucleotides that are the same (i.e., about 60% identity, preferably 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or higher identity over a specified region, when compared and aligned for maximum correspondence over a comparison window or designated region) as measured using a BLAST or BLAST 2.0 sequence comparison algorithms with default parameters described below, or by manual alignment and visual inspection (see, e.g., NCBI web site ncbi.nlm.nih.gov/BLAST/ or the like). Such sequences are then said to be “substantially identical.” The present invention provides for, e.g., antibodies having polynucleotide or polypeptide sequences that have at least 80% identity, e.g., 85%, 90%, 91%, 92%, 93, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity, to a reference sequence, e.g., CDRs or variable regions of any of antibodies ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20. As described below, the preferred algorithms can account for gaps and the like. Preferably, identity exists over a region that is at least about 25 amino acids or nucleotides in length, or more preferably over a region that is 50-100 or more amino acids or nucleotides in length.

For sequence comparison, typically one sequence acts as a reference sequence, to which test sequences are compared. When using a sequence comparison algorithm, test and reference sequences are entered into a computer, subsequence coordinates are designated, if necessary, and sequence algorithm program parameters are designated. Preferably, default program parameters can be used, or alternative parameters can be designated. The sequence comparison algorithm then calculates the percent sequence identities for the test sequences relative to the reference sequence, based on the program parameters.

A “comparison window”, as used herein, includes reference to a segment of any one of the number of contiguous positions selected from the group consisting of from 20 to 600, usually about 50 to about 200, more usually about 100 to about 150 in which a sequence may be compared to a reference sequence of the same number of contiguous positions after the two sequences are optimally aligned. Methods of alignment of sequences for comparison are well-known in the art. Optimal alignment of sequences for comparison can be conducted, e.g., by the local homology algorithm of Smith & Waterman, Adv. Appl. Math. 2:482 (1981), by the homology alignment algorithm of Needleman & Wunsch, J. Mol. Biol. 48:443 (1970), by the search for similarity method of Pearson & Lipman, Proc. Nat'l. Acad. Sci. USA 85:2444 (1988), by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, Wis.), or by manual alignment and visual inspection (see, e.g., Current Protocols in Molecular Biology (Ausubel et al., eds. 1995 supplement)).

An algorithm that is suitable for determining percent sequence identity and sequence similarity are the BLAST and BLAST 2.0 algorithms, which are described in Altschul et al., Nuc. Acids Res. 25:3389-3402 (1977) and Altschul et al., J. Mol. Biol. 215:403-410 (1990), respectively. BLAST and BLAST 2.0 are used, with the parameters described herein, to determine percent sequence identity for the nucleic acids and proteins of the invention. Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information (http://www.ncbi.nlm.nih.gov/). This algorithm involves first identifying high scoring sequence pairs (HSPs) by identifying short words of length W in the query sequence, which either match or satisfy some positive-valued threshold score T when aligned with a word of the same length in a database sequence. T is referred to as the neighborhood word score threshold (Altschul et al., supra). These initial neighborhood word hits act as seeds for initiating searches to find longer HSPs containing them. The word hits are extended in both directions along each sequence for as far as the cumulative alignment score can be increased. Cumulative scores are calculated using, for nucleotide sequences, the parameters M (reward score for a pair of matching residues; always >0) and N (penalty score for mismatching residues; always <0). For amino acid sequences, a scoring matrix is used to calculate the cumulative score. Extension of the word hits in each direction are halted when: the cumulative alignment score falls off by the quantity X from its maximum achieved value; the cumulative score goes to zero or below, due to the accumulation of one or more negative-scoring residue alignments; or the end of either sequence is reached. The BLAST algorithm parameters W, T, and X determine the sensitivity and speed of the alignment. The BLASTN program (for nucleotide sequences) uses as defaults a wordlength (W) of 11, an expectation (E) of 10, M=5, N=−4 and a comparison of both strands. For amino acid sequences, the BLASTP program uses as defaults a wordlength of 3, and expectation (E) of 10, and the BLOSUM62 scoring matrix (see Henikoff & Henikoff, Proc. Natl. Acad. Sci. USA 89:10915 (1989)) alignments (B) of 50, expectation (E) of 10, M=5, N=−4, and a comparison of both strands.

“Nucleic acid” refers to deoxyribonucleotides or ribonucleotides and polymers thereof in either single- or double-stranded form, and complements thereof. The term encompasses nucleic acids containing known nucleotide analogs or modified backbone residues or linkages, which are synthetic, naturally occurring, and non-naturally occurring, which have similar binding properties as the reference nucleic acid, and which are metabolized in a manner similar to the reference nucleotides. Examples of such analogs include, without limitation, phosphorothioates, phosphoramidates, methyl phosphonates, chiral-methyl phosphonates, 2-O-methyl ribonucleotides, peptide-nucleic acids (PNAs).

Unless otherwise indicated, a particular nucleic acid sequence also implicitly encompasses conservatively modified variants thereof (e.g., degenerate codon substitutions) and complementary sequences, as well as the sequence explicitly indicated. Specifically, degenerate codon substitutions may be achieved by generating sequences in which the third position of one or more selected (or all) codons is substituted with mixed-base and/or deoxyinosine residues (Batzer et al., Nucleic Acid Res. 19:5081 (1991); Ohtsuka et al., J. Biol. Chem. 260:2605-2608 (1985); Rossolini et al., Mol. Cell. Probes 8:91-98 (1994)).

The terms “polypeptide,” “peptide” and “protein” are used interchangeably herein to refer to a polymer of amino acid residues. The terms encompass to amino acid polymers in which one or more amino acid residue is an artificial chemical mimetic of a corresponding naturally occurring amino acid, as well as to naturally occurring amino acid polymers and non-naturally occurring amino acid polymer.

The term “amino acid” refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to the naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those amino acids that are later modified, e.g., hydroxyproline, γ-carboxyglutamate, and O-phosphoserine. Amino acid analogs refers to compounds that have the same basic chemical structure as a naturally occurring amino acid, i.e., an a carbon that is bound to a hydrogen, a carboxyl group, an amino group, and an R group, e.g., homoserine, norleucine, methionine sulfoxide, methionine methyl sulfonium. Such analogs have modified R groups (e.g., norleucine) or modified peptide backbones, but retain the same basic chemical structure as a naturally occurring amino acid. Amino acid mimetics refers to chemical compounds that have a structure that is different from the general chemical structure of an amino acid, but that functions in a manner similar to a naturally occurring amino acid.

Amino acids may be referred to herein by either their commonly known three letter symbols or by the one-letter symbols recommended by the IUPAC-IUB Biochemical Nomenclature Commission. Nucleotides, likewise, may be referred to by their commonly accepted single-letter codes.

“Conservatively modified variants” applies to both amino acid and nucleic acid sequences. With respect to particular nucleic acid sequences, conservatively modified variants refers to those nucleic acids which encode identical or essentially identical amino acid sequences, or where the nucleic acid does not encode an amino acid sequence, to essentially identical sequences. Because of the degeneracy of the genetic code, a large number of functionally identical nucleic acids encode any given protein. For instance, the codons GCA, GCC, GCG and GCU all encode the amino acid alanine Thus, at every position where an alanine is specified by a codon, the codon can be altered to any of the corresponding codons described without altering the encoded polypeptide. Such nucleic acid variations are “silent variations,” which are one species of conservatively modified variations. Every nucleic acid sequence herein which encodes a polypeptide also describes every possible silent variation of the nucleic acid. One of skill will recognize that each codon in a nucleic acid (except AUG, which is ordinarily the only codon for methionine, and TGG, which is ordinarily the only codon for tryptophan) can be modified to yield a functionally identical molecule. Accordingly, each silent variation of a nucleic acid which encodes a polypeptide is implicit in each described sequence with respect to the expression product, but not with respect to actual probe sequences.

As to amino acid sequences, one of skill will recognize that individual substitutions, deletions or additions to a nucleic acid, peptide, polypeptide, or protein sequence which alters, adds or deletes a single amino acid or a small percentage of amino acids in the encoded sequence is a “conservatively modified variant” where the alteration results in the substitution of an amino acid with a chemically similar amino acid. Conservative substitution tables providing functionally similar amino acids are well known in the art. Such conservatively modified variants are in addition to and do not exclude polymorphic variants, interspecies homologs, and alleles of the invention.

The following eight groups each contain amino acids that are conservative substitutions for one another: 1) Alanine (A), Glycine (G); 2) Aspartic acid (D), Glutamic acid (E); 3) Asparagine (N), Glutamine (Q); 4) Arginine (R), Lysine (K); 5) Isoleucine (I), Leucine (L), Methionine (M), Valine (V); 6) Phenylalanine (F), Tyrosine (Y), Tryptophan (W); 7) Serine (S), Threonine (T); and 8) Cysteine (C), Methionine (M) (see, e.g., Creighton, Proteins (1984)).

A “label” or a “detectable moiety” is a composition detectable by spectroscopic, photochemical, biochemical, immunochemical, chemical, or other physical means. For example, useful labels include ³²P, fluorescent dyes, electron-dense reagents, enzymes (e.g., as commonly used in an ELISA), biotin, digoxigenin, or haptens and proteins which can be made detectable, e.g., by incorporating a radiolabel into the peptide or used to detect antibodies specifically reactive with the peptide.

The term “recombinant” when used with reference, e.g., to a cell, or nucleic acid, protein, or vector, indicates that the cell, nucleic acid, protein or vector, has been modified by the introduction of a heterologous nucleic acid or protein or the alteration of a native nucleic acid or protein, or that the cell is derived from a cell so modified. Thus, for example, recombinant cells express genes that are not found within the native (non-recombinant) form of the cell or express native genes that are otherwise abnormally expressed, under expressed or not expressed at all.

The term “heterologous” when used with reference to portions of a nucleic acid indicates that the nucleic acid comprises two or more subsequences that are not found in the same relationship to each other in nature. For instance, the nucleic acid is typically recombinantly produced, having two or more sequences from unrelated genes arranged to make a new functional nucleic acid, e.g., a promoter from one source and a coding region from another source. Similarly, a heterologous protein indicates that the protein comprises two or more subsequences that are not found in the same relationship to each other in nature (e.g., a fusion protein).

An antibody as described herein can consist of one or more polypeptides substantially encoded by immunoglobulin genes or fragments of immunoglobulin genes. The recognized immunoglobulin genes include the kappa, lambda, alpha, gamma, delta, epsilon and mu constant region genes, as well as myriad immunoglobulin variable region genes. Light chains are classified as either kappa or lambda. Heavy chains are classified as gamma, mu, alpha, delta, or epsilon, which in turn define the immunoglobulin classes, IgG, IgM, IgA, IgD and IgE, respectively. In some embodiments, the antibody is IgG (e.g., IgG1, IgG2, IgG3, IgG4), IgM, IgA, IgD, or IgE.

A typical immunoglobulin (antibody) structural unit is known to comprise a tetramer. Each tetramer is composed of two identical pairs of polypeptide chains, each pair having one “light” (about 25 kD) and one “heavy” chain (about 50-70 kD). The N-terminus of each chain defines a variable region of about 100 to 110 or more amino acids primarily responsible for antigen recognition. The terms variable light chain (V_(L)) and variable heavy chain (V_(H)) refer to these light and heavy chains respectively.

The term “antibody” as used herein includes antibody fragments that retain binding specificity. For example, there are a number of well characterized antibody fragments. Thus, for example, pepsin digests an antibody C-terminal to the disulfide linkages in the hinge region to produce F(ab)′2, a dimer of Fab which itself is a light chain joined to VH-CH1 by a disulfide bond. The F(ab)′2 may be reduced under mild conditions to break the disulfide linkage in the hinge region thereby converting the (Fab′)2 dimer into an Fab′ monomer. The Fab′ monomer is essentially an Fab with part of the hinge region (see, Fundamental Immunology, W. E. Paul, ed., Raven Press, N.Y. (1993), for a more detailed description of other antibody fragments). While various antibody fragments are defined in terms of the digestion of an intact antibody, one of skill will appreciate that fragments can be synthesized de novo either chemically or by utilizing recombinant DNA methodology. Thus, the term antibody, as used herein also includes antibody fragments either produced by the modification of whole antibodies or synthesized using recombinant DNA methodologies.

In an antibody, substitution variants have at least one amino acid residue removed and a different residue inserted in its place. The sites of greatest interest for substitutional mutagenesis include the hypervariable regions, but framework alterations are also contemplated. Examples of conservative substitutions are described above.

Substantial modifications in the biological properties of the antibody are accomplished by selecting substitutions that differ significantly in their effect on maintaining (a) the structure of the polypeptide backbone in the area of the substitution, for example, as a β-sheet or helical conformation, (b) the charge or hydrophobicity of the molecule at the target site, or (c) the bulk of the side chain. Naturally occurring residues are divided into groups based on common side-chain properties:

-   -   (1) Non-polar: Norleucine, Met, Ala, Val, Leu, Ile;     -   (2) Polar without charge: Cys, Ser, Thr, Asn, Gln;     -   (3) Acidic (negatively charged): Asp, Glu;     -   (4) Basic (positively charged): Lys, Arg;     -   (5) Residues that influence chain orientation: Gly, Pro; and     -   (6) Aromatic: Trp, Tyr, Phe, His.         Non-conservative substitutions are made by exchanging a member         of one of these classes for another class.

One type of substitution that can be made is to change one or more cysteines in the antibody, which may be chemically reactive, to another residue, such as, without limitation, alanine or serine. For example, there can be a substitution of a non-canonical cysteine. The substitution can be made in a CDR or framework region of a variable domain or in the constant region of an antibody. In some embodiments, the cysteine is canonical (e.g., involved in di-sulfide bond formation). Any cysteine residue not involved in maintaining the proper conformation of the antibody also may be substituted, generally with serine, to improve the oxidative stability of the molecule and prevent aberrant cross-linking. Conversely, cysteine bond(s) may be added to the antibody to improve its stability, particularly where the antibody is an antibody fragment such as an Fv fragment.

Antibodies include V_(H)-V_(L) dimers, including single chain antibodies (antibodies that exist as a single polypeptide chain), such as single chain Fv antibodies (sFv or scFv) in which a variable heavy and a variable light region are joined together (directly or through a peptide linker) to form a continuous polypeptide. The single chain Fv antibody is a covalently linked V_(H)-V_(L) which may be expressed from a nucleic acid including V_(H)- and V_(L)-encoding sequences either joined directly or joined by a peptide-encoding linker (e.g., Huston, et al. Proc. Nat. Acad. Sci. USA, 85:5879-5883, 1988). While the V_(H) and V_(L) are connected to each as a single polypeptide chain, the V_(H) and V_(L) domains associate non-covalently. Alternatively, the antibody can be another fragment. Other fragments can also be generated, e.g., using recombinant techniques, as soluble proteins or as fragments obtained from display methods. Antibodies can also include diantibodies and miniantibodies. Antibodies of the invention also include heavy chain dimers, such as antibodies from camelids. For the purposes of this inventor, antibodies are employed in a form that can activate EphA3 present on the surface of myeloproliferative cells or that can kill myeloproliferative cells by ADCC. Thus, in some embodiments an antibody is dimeric. In other embodiments, the antibody may be in a monomeric form that has an active isotype. In some embodiments the antibody is in a multivalent form, e.g., a trivalent or tetravalent form, that can cross-link EphA3.

As used herein, “V-region” refers to an antibody variable region domain comprising the segments of Framework (FW) 1, complementarity-determining region (CDR) 1, FW2, CDR2, FW3, CDR3, and Framework 4. The V region for the heavy and light chains is commonly designated V_(H) and V_(L), respectively, or with like terms. The V region is included on Fab, F(ab′)₂, Fv and scFv antibody fragments described herein, and involved in specific antigen recognition.

As used herein, “complementarity-determining region (CDR)” refers to the three hypervariable regions in each chain that interrupt the four “framework (FW)” regions established by the light and heavy chain variable regions. The CDRs are primarily responsible for binding to an epitope of an antigen. The CDRs of each chain are typically referred to as CDR1, CDR2, and CDR3, numbered sequentially starting from the N-terminus, and are also typically identified by the chain in which the particular CDR is located. Thus, a V_(H) CDR3 is located in the variable domain of the heavy chain of the antibody in which it is found, whereas a V_(L) CDR1 is the CDR1 from the variable domain of the light chain of the antibody in which it is found.

The sequences of the framework regions of different light or heavy chains are relatively conserved within a species. The framework region of an antibody, that is the combined framework regions of the constituent light and heavy chains, serves to position and align the CDRs in three dimensional space.

The amino acid sequences of the CDRs and framework regions can be determined using various well known definitions in the art, e.g., Kabat, Chothia, international ImMunoGeneTics database (IMGT), and AbM (see, e.g., Johnson et al., supra; Chothia & Lesk, 1987, Canonical structures for the hypervariable regions of immunoglobulins. J. Mol. Biol. 196, 901-917; Chothia C. et al., 1989, Conformations of immunoglobulin hypervariable regions. Nature 342, 877-883; Chothia C. et al., 1992, structural repertoire of the human VH segments J. Mol. Biol. 227, 799-817; Al-Lazikani et al., J. Mol. Biol 1997, 273(4)). Definitions of antigen combining sites are also described in the following: Ruiz et al., IMGT, the international ImMunoGeneTics database. Nucleic Acids Res., 28, 219-221 (2000); and Lefranc, M.-P. IMGT, the international ImMunoGeneTics database. Nucleic Acids Res. Jan 1;29(1):207-9 (2001); MacCallum et al, Antibody-antigen interactions: Contact analysis and binding site topography, J. Mol. Biol., 262 (5), 732-745 (1996); and Martin et al, Proc. Natl Acad. Sci. USA, 86, 9268-9272 (1989); Martin, et al, Methods Enzymol., 203, 121-153, (1991); Pedersen et al, Immunomethods, 1, 126, (1992); and Rees et al, In Sternberg M. J. E. (ed.), Protein Structure Prediction. Oxford University Press, Oxford, 141-172 1996).

As used herein, “chimeric antibody” refers to an immunoglobulin molecule in which (a) the constant region, or a portion thereof, is altered, replaced or exchanged so that the antigen binding site (variable region) is linked to a constant region of a different or altered class, effector function and/or species, or an entirely different molecule which confers new properties to the chimeric antibody, e.g., an enzyme, toxin, hormone, growth factor, drug, etc.; or (b) the variable region, or a portion thereof, is altered, replaced or exchanged with a variable region, or portion thereof, having a different or altered antigen specificity; or with corresponding sequences from another species or from another antibody class or subclass.

As used herein, “humanized antibody” refers to an immunoglobulin molecule in CDRs from a donor antibody are grafted onto human framework sequences. Humanized antibodies may also comprise residues of donor origin in the framework sequences. The humanized antibody can also comprise at least a portion of a human immunoglobulin constant region. Humanized antibodies may also comprise residues which are found neither in the recipient antibody nor in the imported CDR or framework sequences. Humanization can be performed using methods known in the art (e.g., Jones et al., Nature 321:522-525; 1986; Riechmann et al., Nature 332:323-327, 1988; Verhoeyen et al., Science 239:1534-1536, 1988); Presta, Curr. Op. Struct. Biol. 2:593-596, 1992; U.S. Pat. No. 4,816,567), including techniques such as “superhumanizing” antibodies (Tan et al., J. Immunol. 169: 1119, 2002) and “resurfacing” (e.g., Staelens et al., Mol. Immunol. 43: 1243, 2006; and Roguska et al., Proc. Natl. Acad. Sci USA 91: 969, 1994).

The terms “antigen,” “immunogen,” “antibody target,” “target analyte,” and like terms are used herein to refer to a molecule, compound, or complex that is recognized by an antibody, i.e., can be specifically bound by the antibody. The term can refer to any molecule that can be specifically recognized by an antibody, e.g., a polypeptide, polynucleotide, carbohydrate, lipid, chemical moiety, or combinations thereof (e.g., phosphorylated or glycosylated polypeptides, etc.). One of skill will understand that the term does not indicate that the molecule is immunogenic in every context, but simply indicates that it can be targeted by an antibody.

Antibodies bind to an “epitope” on an antigen. The epitope is the localized site on the antigen that is recognized and bound by the antibody. Epitopes can include a few amino acids or portions of a few amino acids, e.g., 5 or 6, or more, e.g., 20 or more amino acids, or portions of those amino acids. In some cases, the epitope includes non-protein components, e.g., from a carbohydrate, nucleic acid, or lipid. In some cases, the epitope is a three-dimensional moiety. Thus, for example, where the target is a protein, the epitope can be comprised of consecutive amino acids, or amino acids from different parts of the protein that are brought into proximity by protein folding (e.g., a discontinuous epitope). The same is true for other types of target molecules that form three-dimensional structures. An epitope typically includes at least 3, and more usually, at least 5 or 8-10 amino acids in a unique spatial conformation. Methods of determining spatial conformation of epitopes include, for example, x-ray crystallography and 2-dimensional nuclear magnetic resonance. See, e.g., Epitope Mapping Protocols in Methods in Molecular Biology, Vol. 66, Glenn E. Morris, Ed (1996).

A “label” or a “detectable moiety” is a diagnostic agent or component detectable by spectroscopic, radiological, photochemical, biochemical, immunochemical, chemical, or other physical means. Exemplary labels include radiolabels (e.g., ¹¹¹In, ^(99m)Tc, ¹³¹I, ⁶⁷Ga) and other FDA-approved imaging agents. Additional labels include ³²P, fluorescent dyes, electron-dense reagents, enzymes, biotin, digoxigenin, or haptens and proteins or other entities which can be made detectable, e.g., by incorporating a radiolabel into the targeting agent. Any method known in the art for conjugating a nucleic acid or nanocarrier to the label may be employed, e.g., using methods described in Hermanson, Bioconjugate Techniques 1996, Academic Press, Inc., San Diego.

A “labeled” or “tagged” antibody or agent is one that is bound, either covalently, through a linker or a chemical bond, or noncovalently, through ionic, van der Waals, electrostatic, or hydrogen bonds to a label such that the presence of the antibody or agent may be detected by detecting the presence of the label bound to the antibody or agent.

Techniques for conjugating detectable and therapeutic agents to antibodies are well known (see, e.g., Amon et al., “Monoclonal Antibodies For Immunotargeting Of Drugs In Cancer Therapy”, in Monoclonal Antibodies And Cancer Therapy, Reisfeld et al. (eds.), pp. 243-56 (Alan R. Liss, Inc. 1985); Hellstrom et al., “Antibodies For Drug Delivery” in Controlled Drug Delivery (2nd Ed.), Robinson et al. (eds.), pp. 623-53 (Marcel Dekker, Inc. 1987); Thorpe, “Antibody Carriers Of Cytotoxic Agents In Cancer Therapy: A Review” in Monoclonal Antibodies '84: Biological And Clinical Applications, Pinchera et al. (eds.), pp. 475-506 (1985); and Thorpe et al., “The Preparation And Cytotoxic Properties Of Antibody-Toxin Conjugates”, Immunol. Rev., 62:119-58 (1982)).

The terms “specific for,” “specifically binds,” and like terms refer to a molecule (e.g., antibody or antibody fragment) that binds to a target with at least 2-fold greater affinity than non-target compounds, e.g., at least any of 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 20-fold, 25-fold, 50-fold, or 100-fold greater affinity. For example, an antibody that specifically binds a primary antibody will typically bind the primary antibody with at least a 2-fold greater affinity than a non-primary antibody target (e.g., an antibody from a different species or of a different isotype, or a non-antibody target). Specificity can be determined using standard methods, e.g., solid-phase ELISA immunoassays (see, e.g., Harlow & Lane, Using Antibodies, A Laboratory Manual (1998) for a description of immunoassay formats and conditions that can be used to determine specific immunoreactivity).

The term “binds” with respect to an antibody target (e.g., antigen, analyte, immune complex), typically indicates that an antibody binds a majority of the antibody targets in a pure population (assuming appropriate molar ratios). For example, an antibody that binds a given antibody target typically binds to at least ⅔ of the antibody targets in a solution (e.g., at least any of 75, 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100%). One of skill will recognize that some variability will arise depending on the method and/or threshold of determining binding.

A “control” sample or value refers to a sample that serves as a reference, usually a known reference, for comparison to a test sample. For example, a test sample can be taken from a test condition, e.g., in the presence of a test compound, and compared to samples from known conditions, e.g., in the absence of the test compound (negative control), or in the presence of a known compound (positive control). A control can also represent an average value or a range gathered from a number of tests or results. One of skill in the art will recognize that controls can be designed for assessment of any number of parameters. For example, a control can be devised to compare therapeutic benefit based on pharmacological data (e.g., half-life) or therapeutic measures (e.g., comparison of benefit and/or side effects). Controls can be designed for in vitro applications. One of skill in the art will understand which controls are valuable in a given situation and be able to analyze data based on comparisons to control values. Controls are also valuable for determining the significance of data. For example, if values for a given parameter are widely variant in controls, variation in test samples will not be considered as significant.

The terms “therapeutically effective dose,” “effective dose,” or “therapeutically effective amount” herein is meant a dose that produces effects for which it is administered. The exact dose and formulation will depend on the purpose of the treatment, and will be ascertainable by one skilled in the art using known techniques (see, e.g., Lieberman, Pharmaceutical Dosage Forms (vols. 1-3, 1992); Lloyd, The Art, Science and Technology of Pharmaceutical Compounding (1999); Remington: The Science and Practice of Pharmacy, 20th Edition, Gennaro, Editor (2003), and Pickar, Dosage Calculations (1999)). For example, for the given parameter, a therapeutically effective amount will show an increase or decrease of therapeutic effect at least any of 5%, 10%, 15%, 20%, 25%, 40%, 50%, 60%, 75%, 80%, 90%, or at least 100%. Therapeutic efficacy can also be expressed as “-fold” increase or decrease. For example, a therapeutically effective amount can have at least any of a 1.2-fold, 1.5-fold, 2-fold, 5-fold, or more effect over a control.

The term “pharmaceutically acceptable salts” or “pharmaceutically acceptable carrier” is meant to include salts of the active compounds which are prepared with relatively nontoxic acids or bases, depending on the particular substituents found on the antibodies described herein. Examples of pharmaceutically acceptable base addition salts include sodium, potassium, calcium, ammonium, organic amino, or magnesium salt, or a similar salt. When compounds of the present invention contain relatively basic functionalities, acid addition salts can be obtained by contacting the neutral form of such compounds with a sufficient amount of the desired acid, either neat or in a suitable inert solvent. Examples of pharmaceutically acceptable acid addition salts include those derived from inorganic acids like hydrochloric, hydrobromic, nitric, carbonic, monohydrogencarbonic, phosphoric, monohydrogenphosphoric, dihydrogenphosphoric, sulfuric, monohydrogensulfuric, hydriodic, or phosphorous acids and the like, as well as the salts derived from relatively nontoxic organic acids like acetic, propionic, isobutyric, maleic, malonic, benzoic, succinic, suberic, fumaric, lactic, mandelic, phthalic, benzenesulfonic, p-tolylsulfonic, citric, tartaric, methanesulfonic, and the like. Also included are salts of amino acids such as arginate and the like, and salts of organic acids like glucuronic or galactunoric acids and the like (see, e.g., Berge et al., Journal of Pharmaceutical Science 66:1-19 (1977)). Certain specific compounds of the present invention contain both basic and acidic functionalities that allow the compounds to be converted into either base or acid addition salts. Other pharmaceutically acceptable carriers known to those of skill in the art are suitable for the present invention.

The term “reduce,” “reducing,” or “reduction,” when used in the context of αvβ8-mediate TGFβ activation refers to any detectable negative change or decrease in quantity of a parameter that reflects TGFβ activation, compared to a standard value obtained under the same conditions but in the absence of an antibody as described herein (e.g., anti-αvβ8 antibodies). The level of this decrease following exposure to an antibody as described herein (e.g., anti-αvβ8 antagonists, anti-αvβ8 antibodies and immunoconjugates) is, in some embodiments, at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 100%.

The term “compete”, as used herein with regard to an antibody, means that a first antibody, or an antigen-binding portion thereof, competes for binding with a second antibody, or an antigen-binding portion thereof, where binding of the first antibody with its cognate epitope is detectably decreased in the presence of the second antibody compared to the binding of the first antibody in the absence of the second antibody. The alternative, where the binding of the second antibody to its epitope is also detectably decreased in the presence of the first antibody, can, but need not be the case. That is, a first antibody can inhibit the binding of a second antibody to its epitope without that second antibody inhibiting the binding of the first antibody to its respective epitope. However, where each antibody detectably inhibits the binding of the other antibody with its cognate epitope or ligand, whether to the same, greater, or lesser extent, the antibodies are said to “cross-compete” with each other for binding of their respective epitope(s). Both competing and cross-competing antibodies are encompassed by the present invention. Regardless of the mechanism by which such competition or cross-competition occurs (e.g., steric hindrance, conformational change, or binding to a common epitope, or portion thereof, and the like), the skilled artisan would appreciate, based upon the teachings provided herein, that such competing and/or cross-competing antibodies are encompassed and can be useful for the methods disclosed herein.

Numerous types of competitive binding assays are known, for example: solid phase direct or indirect radioimmunoassay (RIA), solid phase direct or indirect enzyme immunoassay (EIA), sandwich competition assay (see Stahli et al., Methods in Enzymology 9:242-253 (1983)); solid phase direct biotin-avidin EIA (see Kirkland et al., J. Immunol. 137:3614-3619 (1986)); solid phase direct labeled assay, solid phase direct labeled sandwich assay (see Harlow and Lane, Antibodies, A Laboratory Manual, Cold Spring Harbor Press (1988)); solid phase direct label RIA using I-125 label (see Morel et al., Molec. Immunol. 25(1):7-15 (1988)); solid phase direct biotin-avidin EIA (Cheung et al., Virology 176:546-552 (1990)); and direct labeled RIA (Moldenhauer et al., Scand. J. Immunol. 32:77-82 (1990)). Typically, such an assay involves the use of purified antigen bound to a solid surface or cells bearing either of these, an unlabelled test immunoglobulin and a labeled reference immunoglobulin. Competitive inhibition is measured by determining the amount of label bound to the solid surface or cells in the presence of the test immunoglobulin. Usually the test immunoglobulin is present in excess. Antibodies identified by competition assay (competing antibodies) include antibodies binding to the same epitope as the reference antibody and antibodies binding to an adjacent epitope sufficiently proximal to the epitope bound by the reference antibody for steric hindrance to occur. Usually, when a competing antibody is present in excess, it will inhibit specific binding of a reference antibody to a common antigen by at least 50 or 75%.

III. Antibodies that Bind Integrin β8

Antibodies (including antibody fragments) that specifically bind to human integrin β8 are provided, as well as methods for treating or preventing diseases for which decrease of TGFβ activation has an ameliorative effect. “Integrin β8” is used interchangeably with β8 and beta-8. The human integrin β8 protein sequence can be found at Uniprot accession number P26012, while the murine integrin β8 sequence has Uniprot accession number Q0VBD0. See, also, Moyle et al. Journal of Biological Chemistry 266:19650-19658 (1991); Nishimura et al., J. Biological Chemistry 269:28708-28715 (1994).

In some embodiments, an antibody that specifically binds to human integrin β8 and inhibits (partially or completely blocks) binding of latency associated peptide (LAP) to αvβ8 is provided. LAP is a ligand for αvβ8. See, e.g., Sheppard, Cancer and Metastasis Reviews 24(3):395-402 (2005); Lu et al. J Cell Sci 115:4641-4648 (2002). As shown in FIG. 2, antibodies described in the Example inhibit biding of LAP to αvβ8. Antibodies can antagonize LAP binding to αvβ8 with an IC₅₀ of, for example, less than e.g., 10, 5, 1, 0.1 nM or lower.

In some embodiments, an antibody of the invention specifically binds to mouse as well as human integrin β8. Each of antibodies ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20 bind to both human and mouse β8. One advantage of such antibodies is that clinical data can be generated for these antibodies in mice as well as humans.

One aspect of blockage of LAP binding to αvβ8 in a cell can be that the antibodies prevent or reduce TGFβ activate in the cell. Thus, in some embodiments, the antibodies described herein are useful for decreasing TGFβ activation in a cell or an animal (e.g., a mouse, human, or other animal).

In some embodiments, the antibodies compete with one of more antibodies selected from ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20. In some embodiments, the antibodies bind to the same epitope as bound by ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20. Monoclonal antibodies, and chimeric, and especially humanized antibodies, are of particular use for human therapeutic uses of the antibodies described herein. Thus, in some embodiments, a αvβ8-specific antibody as described herein comprises the complementarity determining regions (CDRs) of the heavy chain variable region and the light chain variable region of an antibody selected from ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20. For example, the antibody can have CDR1, CDR2, and CDR3 of the heavy chain variable region and CDR1, CDR2, and CDR3 of the light chain variable region of an antibody selected from ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20 and have a heterologous (e.g., human or human-like) framework region.

In some embodiments, the αvβ8-specific antibodies as described herein comprise the complementarity determining regions (CDRs) of the heavy chain variable region sequence and the light chain variable region sequence selected from:

SEQ ID NO:1 and SEQ ID NO:16, respectively;

SEQ ID NO:2 and SEQ ID NO:16, respectively;

SEQ ID NO:3 and SEQ ID NO:16, respectively;

SEQ ID NO:4 and SEQ ID NO:16, respectively;

SEQ ID NO:5 and SEQ ID NO:16, respectively;

SEQ ID NO:6 and SEQ ID NO:16, respectively;

SEQ ID NO:7 and SEQ ID NO:17, respectively;

SEQ ID NO:8 and SEQ ID NO:18, respectively;

SEQ ID NO:9 and SEQ ID NO:19, respectively;

SEQ ID NO:10 and SEQ ID NO:20, respectively;

SEQ ID NO:11 and SEQ ID NO:20, respectively;

SEQ ID NO:12 and SEQ ID NO:20, respectively;

SEQ ID NO:13 and SEQ ID NO:20, respectively;

SEQ ID NO:14 and SEQ ID NO:21, respectively; and

SEQ ID NO:15 and SEQ ID NO:22, respectively.

In some embodiments, the αvβ8-specific antibodies as described herein comprise the heavy chain variable region sequence and the light chain variable region sequence of selected from:

SEQ ID NO:1 and SEQ ID NO:16, respectively;

SEQ ID NO:2 and SEQ ID NO:16, respectively;

SEQ ID NO:3 and SEQ ID NO:16, respectively;

SEQ ID NO:4 and SEQ ID NO:16, respectively;

SEQ ID NO:5 and SEQ ID NO:16, respectively;

SEQ ID NO:6 and SEQ ID NO:16, respectively;

SEQ ID NO:7 and SEQ ID NO:17, respectively;

SEQ ID NO:8 and SEQ ID NO:18, respectively;

SEQ ID NO:9 and SEQ ID NO:19, respectively;

SEQ ID NO:10 and SEQ ID NO:20, respectively;

SEQ ID NO:11 and SEQ ID NO:20, respectively;

SEQ ID NO:12 and SEQ ID NO:20, respectively;

SEQ ID NO:13 and SEQ ID NO:20, respectively;

SEQ ID NO:14 and SEQ ID NO:21, respectively; and

SEQ ID NO:15 and SEQ ID NO:22, respectively.

In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:1 and SEQ ID NO:16, respectively. In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:4 and SEQ ID NO:16, respectively. In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:7 and SEQ ID NO:17, respectively. In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:8 and SEQ ID NO:18, respectively. In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:9 and SEQ ID NO:19, respectively.

Monoclonal antibodies can be obtained by various techniques familiar to those skilled in the art. Briefly, spleen cells from an animal immunized with a desired antigen are immortalized, commonly by fusion with a myeloma cell (see, for example, Kohler & Milstein, Eur. J. Immunol. 6: 511-519 (1976)). Alternative methods of immortalization include transformation with Epstein Barr Virus, oncogenes, or retroviruses, or other methods well known in the art. Colonies arising from single immortalized cells are screened for production of antibodies of the desired specificity and affinity for the antigen, and yield of the monoclonal antibodies produced by such cells may be enhanced by various techniques, including injection into the peritoneal cavity of a vertebrate host. Alternatively, one may isolate DNA sequences which encode a monoclonal antibody or a binding fragment thereof by screening a DNA library from human B cells according to the general protocol outlined by Huse et al., Science 246: 1275-1281 (1989).

Monoclonal antibodies can be collected and titered against a β8 ligand (e.g., LAP) in an immunoassay, for example, a solid phase immunoassay with the ligand immobilized on a solid support. In some embodiments, monoclonal antibodies will bind with a K_(d) of at least about 0.1 mM, e.g., at least about 1 μM, e.g., at least about 0.1 μM or better, e.g., 0.01 μM or lower.

In an exemplary embodiment, an animal, such as a rabbit or mouse is immunized with a β8 polypeptide, or an nucleic acid construct encoding such a polypeptide. The antibodies produced as a result of the immunization can be isolated using standard methods. In some embodiments, the animal is a knockout of integrin β8 and is immunized with a human β8 integrin polypeptide or a fragment thereof.

The immunoglobulins, including binding fragments and other derivatives thereof, of the present invention may be produced readily by a variety of recombinant DNA techniques, including by expression in transfected cells (e.g., immortalized eukaryotic cells, such as myeloma or hybridoma cells) or in mice, rats, rabbits, or other vertebrate capable of producing antibodies by well-known methods. Suitable source cells for the DNA sequences and host cells for immunoglobulin expression and secretion can be obtained from a number of sources, such as the American Type Culture Collection (Catalogue of Cell Lines and Hybridomas, Fifth edition (1985) Rockville, Md.).

In some embodiments, the antibody is a humanized antibody, i.e., an antibody that retains the reactivity of a non-human antibody while being less immunogenic in humans. This can be achieved, for instance, by retaining the non-human CDR regions and replacing the remaining parts of the antibody with their human counterparts. See, e.g., Morrison et al., PNAS USA, 81:6851-6855 (1984); Morrison and Oi, Adv. Immunol., 44:65-92 (1988); Verhoeyen et al., Science, 239:1534-1536 (1988); Padlan, Molec. Immun., 28:489-498 (1991); Padlan, Molec. Immun., 31(3):169-217 (1994). Techniques for humanizing antibodies are well known in the art and are described in e.g., U.S. Pat. Nos. 4,816,567; 5,530,101; 5,859,205; 5,585,089; 5,693,761; 5,693,762; 5,777,085; 6,180,370; 6,210,671; and 6,329,511; WO 87/02671; EP Patent Application 0173494; Jones et al. (1986) Nature 321:522; and Verhoyen et al. (1988) Science 239:1534. Humanized antibodies are further described in, e.g., Winter and Milstein (1991) Nature 349:293. For example, polynucleotides comprising a first sequence coding for humanized immunoglobulin framework regions and a second sequence set coding for the desired immunoglobulin complementarity determining regions can be produced synthetically or by combining appropriate cDNA and genomic DNA segments. Human constant region DNA sequences can be isolated in accordance with well-known procedures from a variety of human cells. The CDRs for producing the immunoglobulins of the present invention will be similarly derived from monoclonal antibodies capable of specifically binding to αvβ8 integrin (e.g., ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20 or antibodies that compete with ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20 for specific binding to αvβ8 integrin).

In some cases, transfer of a CDR to a human framework leads to a loss of specificity for the humanized antibody. In these cases, back mutation can be introduced into the framework regions of the human portion of the antibody. Methods of making back mutations are well known in the art and are described in, e.g., Co et al., PNAS USA 88;2269-2273 (1991) and WO 90/07861.

In some embodiments, the antibodies are antibody fragments such as Fab, F(ab′)₂, Fv or scFv. The antibody fragments can be generated using any means known in the art including, chemical digestion (e.g., papain or pepsin) and recombinant methods. Methods for isolating and preparing recombinant nucleic acids are known to those skilled in the art (see, Sambrook et al., Molecular Cloning. A Laboratory Manual (2d ed. 1989); Ausubel et al., Current Protocols in Molecular Biology (1995)). The antibodies can be expressed in a variety of host cells, including E. coli, other bacterial hosts, yeast, and various higher eukaryotic cells such as the COS, CHO, and HeLa cells lines and myeloma cell lines.

Competitive binding assays can be used to identify antibodies that compete with an antibody described herein for specific binding to αvβ8 integrin. Any of a number of competitive binding assays known in the art can be used to measure competition between two antibodies to the same antigen. Briefly, the ability of different antibodies to inhibit the binding of another antibody is tested. For example, antibodies can be differentiated by the epitope to which they bind using a sandwich ELISA assay. This is carried out by using a capture antibody to coat the surface of a well. A subsaturating concentration of tagged-antigen is then added to the capture surface. This protein will be bound to the antibody through a specific antibody:epitope interaction. After washing a second antibody, which has been covalently linked to a detectable moiety (e.g., HRP, with the labeled antibody being defined as the detection antibody) is added to the ELISA. If this antibody recognizes the same epitope as the capture antibody it will be unable to bind to the target protein as that particular epitope will no longer be available for binding. If however this second antibody recognizes a different epitope on the target protein it will be able to bind and this binding can be detected by quantifying the level of activity (and hence antibody bound) using a relevant substrate. The background is defined by using a single antibody as both capture and detection antibody, whereas the maximal signal can be established by capturing with an antigen specific antibody and detecting with an antibody to the tag on the antigen. By using the background and maximal signals as references, antibodies can be assessed in a pair-wise manner to determine epitope specificity.

A first antibody is considered to competitively inhibit binding of a second antibody, if binding of the second antibody to the antigen is reduced by at least 30%, usually at least about 40%, 50%, 60% or 75%, and often by at least about 90%, in the presence of the first antibody using any of the assays described above.

IV. Therapeutic Treatment

As discussed above, the antibodies (including antibody fragments) described herein can be used to reduce TGFβ activation in a cell or an animal. Accordingly, the antibodies can be administered to an animal (e.g., a human or non-human animal) in need thereof, thereby reducing TGFβ activation in the animal. Diseases for which reduction of TGFβ is at least ameliorative include, but are not limited to, asthma, multiple sclerosis, acute lung injury, rheumatoid arthritis, psoriasis and chronic obstructive pulmonary disease. For example, the inventors have found that β8 knockout mice have ameliorated symptoms in asthma, multiple sclerosis, and acute lung injury mouse models compared to those mouse models expressing native integrin β8.

Accordingly, compositions, including pharmaceutical compositions, comprising one or more antibody described herein are provided. For example, a pharmaceutical composition comprising a humanized ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, or ADWA-20 antibody is provided.

In some embodiments, the pharmaceutical composition comprises an antibody or antibody fragment comprising the heavy chain CDR sequences (CDR1, CDR2, and CDR3) and light chain CDR sequences (CDR1, CDR2, and CDR3) selected from the group consisting of:

SEQ ID NO:1 and SEQ ID NO:16, respectively;

SEQ ID NO:2 and SEQ ID NO:16, respectively;

SEQ ID NO:3 and SEQ ID NO:16, respectively;

SEQ ID NO:4 and SEQ ID NO:16, respectively;

SEQ ID NO:5 and SEQ ID NO:16, respectively;

SEQ ID NO:6 and SEQ ID NO:16, respectively;

SEQ ID NO:7 and SEQ ID NO:17, respectively;

SEQ ID NO:8 and SEQ ID NO:18, respectively;

SEQ ID NO:9 and SEQ ID NO:19, respectively;

SEQ ID NO:10 and SEQ ID NO:20, respectively;

SEQ ID NO:11 and SEQ ID NO:20, respectively;

SEQ ID NO:12 and SEQ ID NO:20, respectively;

SEQ ID NO:13 and SEQ ID NO:20, respectively;

SEQ ID NO:14 and SEQ ID NO:21, respectively; and

SEQ ID NO:15 and SEQ ID NO:22, respectively.

In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:1 and SEQ ID NO:16, respectively. In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:4 and SEQ ID NO:16, respectively. In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:7 and SEQ ID NO:17, respectively. In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:8 and SEQ ID NO:18, respectively. In some embodiments, the antibody has the heavy chain CDR sequences and light chain CDR sequences found in SEQ ID NO:9 and SEQ ID NO:19, respectively.

The pharmaceutical compositions of the invention may comprise a pharmaceutically acceptable carrier. Pharmaceutically acceptable carriers are determined in part by the particular composition being administered, as well as by the particular method used to administer the composition. Accordingly, there are a wide variety of suitable formulations of pharmaceutical compositions of the present invention (see, e.g., Remington's Pharmaceutical Sciences, 17th ed., 1989).

The compositions of the invention, alone or in combination with other suitable components, can be made into aerosol formulations (i.e., they can be “nebulized”) to be administered via inhalation. Aerosol formulations can be placed into pressurized acceptable propellants, such as dichlorodifluoromethane, propane, nitrogen, and the like.

Formulations suitable for administration include aqueous and non-aqueous solutions, isotonic sterile solutions, which can contain antioxidants, buffers, bacteriostats, and solutes that render the formulation isotonic, and aqueous and non-aqueous sterile suspensions that can include suspending agents, solubilizers, thickening agents, stabilizers, and preservatives. In the practice of this invention, compositions can be administered, for example, orally, nasally, topically, intravenously, intraperitoneally, or intrathecally. The formulations of compounds can be presented in unit-dose or multi-dose sealed containers, such as ampoules and vials. Solutions and suspensions can be prepared from sterile powders, granules, and tablets of the kind previously described. The modulators can also be administered as part a of prepared food or drug.

Formulations suitable for oral administration can comprise: (a) liquid solutions, such as an effective amount of the packaged nucleic acid suspended in diluents, such as water, saline or PEG 400; (b) capsules, sachets or tablets, each containing a predetermined amount of the active ingredient, as liquids, solids, granules or gelatin; (c) suspensions in an appropriate liquid; and (d) suitable emulsions. Tablet forms can include one or more of lactose, sucrose, mannitol, sorbitol, calcium phosphates, corn starch, potato starch, microcrystalline cellulose, gelatin, colloidal silicon dioxide, talc, magnesium stearate, stearic acid, and other excipients, colorants, fillers, binders, diluents, buffering agents, moistening agents, preservatives, flavoring agents, dyes, disintegrating agents, and pharmaceutically compatible carriers. Lozenge forms can comprise the active ingredient in a flavor, e.g., sucrose, as well as pastilles comprising the active ingredient in an inert base, such as gelatin and glycerin or sucrose and acacia emulsions, gels, and the like containing, in addition to the active ingredient, carriers known in the art.

The dose administered to a patient, in the context of the present invention should be sufficient to effect a beneficial response in the subject over time. The optimal dose level for any patient will depend on a variety of factors including the efficacy of the specific modulator employed, the age, body weight, physical activity, and diet of the patient, on a possible combination with other drugs, and on the severity of the PE. The size of the dose also will be determined by the existence, nature, and extent of any adverse side-effects that accompany the administration of a particular compound or vector in a particular subject.

In determining the effective amount of the antagonists of αvβ8 integrin to be administered a physician may evaluate circulating plasma levels of the antagonist and antagonist toxicity. In general, the dose equivalent of an antagonist is from about 1 ng/kg to 10 mg/kg for a typical subject.

For administration, the antagonists of αvβ8 integrin can be administered at a rate determined by the LD₅₀ of the antagonist, and the side-effects of the antagonist at various concentrations, as applied to the mass and overall health of the subject. Administration can be accomplished via single or divided doses.

The compositions may be administered on a regular basis (e.g., daily) for a period of time (e.g., 2, 3, 4, 5, 6, days or 1-3 weeks or more). The compositions can be administered directly to the mammalian subject to reduce TGFβ activation using any route known in the art, including e.g., by injection (e.g., intravenous, intraperitoneal, subcutaneous, intramuscular, or intrademal), inhalation, transdermal application, rectal administration, or oral administration.

EXAMPLES Example 1

Nine antibodies (designated ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-20, and ADWA-25) were identified that block adhesion to TGFβ1 LAP, cross react with murine β8 (as determined with flow cytometry on murine astrocytes) and block TGFβ activation (as determined with β83.7.12-serial dilutions in a co-culture bioassay with mink lung epithelial cells). The most potent antibody, ADWA11, appears to have an IC50 for inhibiting TGFβ activation of less than 5 nM (based on nearly complete inhibition by a concentration of antibody of 1 microgram/ml (˜6.3 nM)).

The antibodies were made by immunizing rare β8 knockout mice that survive into young adulthood with purified human αvβ8. Flow cytometry plots are with primary murine astrocytes and show that ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-20, and ADWA-25 all recognize the mouse integrin, whereas several others do not. See, FIG. 1. The same antibodies block adhesion of β8 transfected SW480 cells to LAP and TGFβ activation by the same cells. See, FIGS. 2 and 3, respectively. Because the cells used also expressed the αvβ6 integrin, the results for these assays also include the β6 blocking antibody, 3G9.

Additional TGFβ activation studies were carried out with individual antibodies to determine their ability to block activation of β8-transfected SNB-19 cells at various concentrations. The results are shown in FIGS. 4-8 for ADWA-2, ADWA-11, ADWA-13, ADWA-15, and ADWA-16. Additional LAP blocking assays were also carried out in β8-transfected SNB-19 cells. Results are shown in FIGS. 9-13.

The results show that ADWA-2, ADWA-16, ADWA-15, ADWA-11, ADWA-13, and ADWA-10 are more effective for blocking LAP adhesion and inhibiting TGFβ activation.

Example 2

In order to further characterize the sequences of the ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-20, and ADWA-25 antibodies, total RNA was harvested from the hybridoma cell line expressing each antibody. RNA was isolated using Qiagen® RNeasy® kit and QIAshredder. Reverse transcriptase PCR was carried out using oligo dT and Clonetech® SMART™ IIa oligo. PCR was carried out using SMART-sense oligo and mouse IgG1 or kappa constant domain oligos.

Each of the 500 bp PCR products (from each antibody clone) was separated using gel electrophoresis, and cloned into Invitrogen™ Zero Blunt® TOPO® cloning kit, and transformed into cells. For each antibody hybridoma clone, 16 colonies were selected (288 total colonies).

The cloned DNA was sequenced by rolling circle amplification (RCA), and analyzed with Invitrogen™ AlignX® and TIBCO® Spotfire®. The CDR and V-region sequences were initially analyzed to determine variability within each antibody clone, and then compared between clones.

Nearly all of the VH sequences of ADWA16 and ADWA2 were identical (SEQ ID NO:1), with 2 variants found in the 16 ADWA2 samples (SEQ ID NOs:2 and 3). The primary ADWA13 sequence is shown in SEQ ID NO:4, with 2 variants shown in SEQ ID NOs:5 and 6. The VH sequences of these three antibodies was quite similar, with 2 amino acid changes in CDR2 (positions 60 and 66) and 3 in the FW regions (positions 19, 45, and 78).

The VH sequences for ADWA10, ADWA11, ADWA15, ADWA20, and ADWA25 were identical within each clone, but distinct from other clones. The VH sequences are shown in SEQ ID NOs: 7 (ADWA15), 8 (ADWA11), 9 (ADWA10), 14 (ADWA20), and 15 (ADWA25). Three VH sequence variants were found among the 16 ADWA8 samples (SEQ ID NOs:11-13), with the primary sequence shown as SEQ ID NO:10.

As for light chains, ADWA2, ADWA13, and ADWA16 were found to share the same Vkappa sequence (SEQ ID NO:16). The Vkappa sequences for ADWA15, ADWA11, and ADWA10 are shown as SEQ ID NOs:17, 18, and 19, respectively. The Vkappa sequences for ADWA8, ADWA20, and ADWA25 are shown as SEQ ID NOs:20, 21, and 22, respectively.

The antibody sequences were confirmed and are shown in Table 1 below. Table 1 shows the sequences for the heavy chain variable (V_(H)) region, light chain variable (V_(L)) region, heavy chain CDRs (HCDR), light chain CDRs (LCDR), V_(H)-encoding nucleotides, and V_(L)-encoding nucleotides. CDRs are shown according to both Chothia (underlined) and Kabat (bold) designations.

TABLE 1  SEQ ID NO: Description Sequence V_(H) SEQUENCES-AMINO ACIDS 1 ADWA2 QVQLQQSGAELAKPGASMKMSCKASGYTFSSY WIYWVKQRPGQGLEWIGYI N ADWA16 PTTGY TEYNQKFRDKATLTADKSSNTAYMQLSSLTSEDSAVYYCAT EGGNWE DY WGQGTTLTVSS 2 ADWA2-1 QVQLQQSGAELAKPGASMKMSCKASGYTFSSY WIYWVKQRPGQGLEWIGYI N PTTGY TEYNQKFRDKVTLTADKSSNTAYMQLSSLTSEDSAVYYCAT EGGNWE DY WGQGTTLTVSS 3 ADWA2-2 QVQLQQSGAELTKPGASMKMSCKASGYTFSSY WIYWVKQRPGQGLEWIGYI N PTTGY TEYNQKFRDKVTLTADKSSNTAYMQLSSLTSEDSAVYYCAT EGGNWE DY WGQGTTLTVSS 4 ADWA13 QVQLQQSGAELAKPGASVKMSCKASGYTFSSY WIYWVKQRPGQVLEWIGYI N PTTGY TDYNQKFKDKATLTADKSSSTAYMQLSSLTSEDSAVYYCAT EGGNWE DY WGQGTTLTVSS 5 ADWA13-1 QVQLQQSGAELAKPGASVKMSCKASGYTFSSY WIYWVKQRPGQVLEWIGYI N PTTGY TDYNQKFKDKATLTADKSSSTAYMQLSSLTSEDSTVYYCAT EGGNWE DY WGQGTTLTVSS 6 ADWA13-2 QVQLQQSGAELTKPGASVKMSCKASGYTFSSY WIYWVKQRPGQVLEWIGYI N PTTGY TDYNQKFKDKATLTADKSSSTAYMQLSSLTSEDSTVYYCAT EGGNWE DY WGQGTTLTVSS 7 ADWA15 QVQLQQPGSVLVRPGASVKLSCKASGYTFTSS WMHWAKQRPGQGLEWIGEI H PNSGN SIYNEKFKDKATLTVDTSSSTAYVDLSSLTSEDSAVYYCAR WGDFDY WGQGTSVTVSS 8 ADWA11 EVQLQQSGAELVRPGAFVKLSCKASGFNIKDY YMNWVLQRPEQGLEWIGWI D PDNGN TIYDPKFQGKASITADTSSNTAYLQLSSLTSEDTAVYYCAR RLLMDY WGQGTSVTVSS 9 ADWA10 EVLLQQSGPELVKPGASVKIPCKASGYTFTNY NMDWVKQSHGKSLEWIGDI N PNSGG SVYNQKFKGKATLTVDKSSSTAYMELRSLTSEDTAVYYCAR WAYYGE RFHYFDY WGQGTTLTVSS 10 ADWA8 QVQLQQPGSELVRPGASVKLSCKASGYTFTSY WMHWVKQRPGQGLEWIGNI Y PGSGR TNYDEKFKSKATLTVDTSSSTAYMQLSSLTSEDSAVYYCTR PLQYRY DVYPMDY WGQGTSVTVSS 11 ADWA8-1 QVQLQQPGSELVRPGASVKLSCKASGYTFTSY WMHWVKQRPGQGLEWIGNI Y PGSGR TNYDEKFRSKATLTVDTSSSTAYMQLSSLTSEDSAVYYCTR PLQYRY DVYPMDY WGQGTSVTVSS 12 ADWA8-2 QVQLQQPGSELVRPGASVKLSCKASGYTFTSY WMHWVKQKPGQGLEWIGNI Y PGSGR TNYDEKFKSKATLTVDTSSSTAYMQLTSLTSEDSAVYYCTRPLQYRY DVYPMDY WGQGTSVTVSS 13 ADWA8-3 QVQLQQPGSELVRPGASMKLSCKASGYTFTSY WMHWVKQRPGQGLEWIGNIY PGSGR TNYDEKFKSKATLTVDTSSSTAYMQLTSLTSEDSAVYYCTR PLQYRY DVYPMDY WGQGTSVTVSS 14 ADWA20 DVQLQESGPGLVKPSQSLSLTCTVTGYSITSDF AWSWIRQFPGNKLEWMGYI SYSGS TGYNPSLKSRISITRDTSKNQFFLQLNSVTTEDTATYYCTR RGLYHW GFPY WGQGTLVTVSA 15 ADWA25 EVQLVESGGDLVKPGGSLKLSCAASGFTESSY GMSWVRQTPDKRLEWVATI S GGGSY TYYPDSVKGRFTISRHNAKNTLYLQMSSLKSEDTAMYYCAS DPYYYG RRDLAWIAY WGQGTLVTVSA V_(L) SEQUENCES-AMINO ACIDS 16 ADWA2 DIQMTQTTSSLSASLGDRVTISC RASQDISNYLN WYQQKPDGTVKLLIY YTS ADWA13 RLYS GVPSRFSGSGSGTDYSLTISNLEPKDIATYYC QQFSELPRT EGGGTKL ADWA16 EIK 17 ADWA15 DVQMTQTTSSLSASLGDRVTISC RASQDISNYLN WYQQKPDGTVKLLIY YTS RLHS GVPSRFSGSGSGTDFSLTISNLEPEDIATYYC QQYNKVPLT FGGGTKL ELK 18 ADWA11 DIVMTQAAPSVPVTPGESVSISC RSTKSLLHENGNTYLF WFLQRPGQSPQRL IY YMSNLAS GVPDRFSGRGSGTDFTLRISRVEAEDVGVYYC MQSLEYPFT FG TGTKLEIK 19 ADWA10 QIVLSQSPAILSASPGEKVTMTC RASSSVSYMH WYQQKSGSSPKPWIY ATSN LAS GVPARFSGSGSGTSYSLTISRVEAEDAATYYC QQWSSNPPT FGGGTKLE IK 20 ADWA8 DIQMTQSPASLSASVGETVTITC RASENIDSYLA WYQQKQGKSPQLLVY AAT LLPD GVPSRFSGSGSGTQYSLKINSLQSEDVARYYC QHYYNTPWT FGGGTKL EIK 21 ADWA20 DIVMTQSHKFMSTSVGDRVSITC KASQDVSSAVA WYQQKPGQSPKLLIY WAS TRHT GVPDRFTGSGSGTDYTLTVSNVQAEDLALYYC QQHYITPYT FGGGTKL EIK 22 ADWA25 DIVMTQSQKFMSTSVGDRVSVTC KASQNVGTNVA WYQQKPGQSPKALIY SAS YRYS GVPDRFTGSGSGTDFTLTISNVQSEDLAEYFC QQYNSYPYT EGGGTKL EIK V_(H) CDR SEQUENCES-AMINO ACIDS 23 ADWA2 GYTFSSY WIY ADWA16 ADWA2-1 ADWA2-2 ADWA13 ADWA13-1 ADWA13-2 HCDR1 24 ADWA2 YI NPTTGY TEYNQKFRD ADWA16 ADWA2-1 ADWA2-2 HCDR2 25 ADWA2 EGGNWEDY ADWA16 ADWA2-1 ADWA2-2 ADWA13 ADWA13-1 ADWA13-2 HCDR3 26 ADWA13 YI NPTTGY TDYNQKFKD ADWA13-1 ADWA13-2 HCDR2 27 ADWA15 GYTFTS S WMH HCDR1 28 ADWA15 EI HPNSGN SIYNEKFKD HCDR2 29 ADWA15 WGDFDY HCDR3 30 ADWA11 GFNIKDY YMN HCDR1 31 ADWA11 WI DPDNGN TIYDPKFQG HCDR2 32 ADWA11 RLLMDY HCDR3 33 ADWA10 GYTFTNY NMD HCDR1 34 ADWA10 DI NPNSGG SVYNQKFKG HCDR2 35 ADWA10 WAYYGERFHYFDY HCDR3 36 ADWA8 GYTFTS Y WMH ADWA8-1 ADWA8-2 ADWA8-3 HCDR1 37 ADWA8 NI YPGSGR TNYDEKFKS ADWA8-2 ADWA8-3 HCDR2 38 ADWA8 PLQYRYDVYPMDY ADWA8-1 ADWA8-2 ADWA8-3 HCDR3 39 ADWA8-1 NI YPGSGR TNYDEKFRS HCDR2 40 ADWA20 GYSITSDF AWS HCDR1 41 ADWA20 YI SYSGS TGYNPSLKS HCDR2 42 ADWA20 RGLYHWGFPY HCDR3 43 ADWA25 GFTFSSY GMS HCDR1 44 ADWA25 TI SGGGSY TYYPDSVKG HCDR2 45 ADWA25 DPYYYGRRDLAWIAY HCDR3 V_(L) CDR SEQUENCES-AMINO ACIDS 46  ADWA2 RASQDISNYLN ADWA13 ADWA16 ADWA15 LCDR1 47 ADWA2 YTSRLYS ADWA13 ADWA16 LCDR2 48 ADWA2 QQFSELPRT ADWA13 ADWA16 LCDR3 49 ADWA15 YTSRLHS LCDR2 50 ADWA15 QQYNKVPLT LCDR3 51 ADWA11 RSTKSLLHFNGNTYLF LCDR1 52 ADWA11 YMSNLAS LCDR2 53 ADWA11 MQSLEYPFT LCDR3 54 ADWA10 RASSSVSYMH LCDR1 55 ADWA10 ATSNLAS LCDR2 56 ADWA10 QQWSSNPPT LCDR3 57 ADWA8 RASENIDSYLA LCDR1 58 ADWA8 AATLLPD LCDR2 59 ADWA8 QHYYNTPWT LCDR3 60 ADWA20 KASQDVSSAVA LCDR1 61 ADWA20 WASTRHT LCDR2 62 ADWA20 QQHYITPYT LCDR3 63 ADWA25 KASQNVGTNVA LCDR1 64 ADWA25 SASYRYS LCDR2 65 ADWA25 QQYNSYPYT LCDR3 V_(H) SEQUENCES-NUCLEIC ACIDS 66 ADWA16-1 CAGGTCCAGCTTCAGCAGTCTGGGGCTGAACTGGCAAAACCTGGGGCCTCAA TGAAGATGTCCTGCAAGGCTTCTGGCTACACCTTTTCTAGCTACTGGATATA TTGGGTAAAACAGAGGCCTGGACAGGGTCTGGAATGGATTGGATACATTAAT CCTACCACTGGTTATACTGAGTACAATCAGAAGTTCAGGGACAAGGCCACAT TGACTGCAGACAAATCCTCCAACACAGCCTACATGCAACTGAGCAGCCTGAC ATCTGAGGACTCTGCAGTCTATTACTGTGCAACAGAGGGAGGTAATTGGGAG GACTACTGGGGCCAAGGCACCACTCTCACAGTCTCCTCA 67 ADWA2-1 CAGGTCCAGCTTCAGCAGTCTGGGGCTGAACTGGCAAAACCTGGGGCCTCAA TGAAGATGTCCTGCAAGGCTTCTGGCTACACCTTTTCTAGCTACTGGATATA TTGGGTAAAACAGAGGCCTGGACAGGGTCTGGAATGGATTGGATACATTAAT CCTACCACTGGTTATACTGAGTACAATCAGAAGTTCAGGGACAAGGTCACAT TGACTGCAGACAAATCCTCCAACACAGCCTACATGCAACTGAGCAGCCTGAC ATCTGAGGACTCTGCAGTCTATTACTGTGCAACAGAGGGAGGTAATTGGGAG GACTACTGGGGCCAAGGCACCACTCTCACAGTCTCCTCA 68 ADWA2-2 CAGGTCCAGCTTCAGCAGTCTGGGGCTGAACTGACAAAACCTGGGGCCTCAA TGAAGATGTCCTGCAAGGCTTCTGGCTACACCTTTTCTAGCTACTGGATATA TTGGGTAAAACAGAGGCCTGGACAGGGTCTGGAATGGATTGGATACATTAAT CCTACCACTGGTTATACTGAGTACAATCAGAAGTTCAGGGACAAGGCCACAT TGACTGCAGACAAATCCTCCAACACAGCCTACATGCAACTGAGCAGCCTGAC ATCTGAGGACTCTGCAGTCTATTACTGTGCAACAGAGGGAGGTAATTGGGAG GACTACTGGGGCCAAGGCACCACTCTCACAGTCTCCTCA 69 ADWA13 CAGGTCCAGCTTCAGCAGTCTGGGGCTGAACTGGCAAAACCTGGGGCCTCAG TGAAGATGTCCTGCAAGGCTTCTGGCTACACCTTTTCTAGCTACTGGATATA TTGGGTAAAACAGAGGCCTGGACAGGTTCTGGAATGGATTGGATACATTAAT CCTACCACTGGTTACACTGACTACAATCAGAAGTTCAAGGACAAGGCCACAT TGACTGCAGACAAATCCTCCAGCACAGCCTACATGCAACTGAGCAGCCTGAC ATCTGAGGACTCTGCAGTCTATTACTGTGCAACAGAGGGAGGTAATTGGGAG GACTACTGGGGCCAAGGCACCACTCTCACAGTCTCCTCA 70 ADWA13-1 CAGGTCCAGCTTCAGCAGTCTGGGGCTGAACTGGCAAAACCTGGGGCCTCAG TGAAGATGTCCTGCAAGGCTTCTGGCTACACCTTTTCTAGCTACTGGATATA TTGGGTAAAACAGAGGCCTGGACAGGTTCTGGAATGGATTGGATACATTAAT CCTACCACTGGTTACACTGACTACAATCAGAAGTTCAAGGACAAGGCCACAT TGACTGCAGACAAATCCTCCAGCACAGCCTACATGCAACTGAGCAGCCTGAC ATCTGAGGACTCTACAGTCTATTACTGTGCAACAGAGGGAGGTAATTGGGAG GACTACTGGGGCCAAGGCACCACTCTCACAGTCTCCTCA 71 ADWA13-2 CAGGTCCAGCTTCAGCAGTCTGGGGCTGAACTGACAAAACCTGGGGCCTCAG TGAAGATGTCCTGCAAGGCTTCTGGCTACACCTTTTCTAGCTACTGGATATA TTGGGTAAAACAGAGGCCTGGACAGGTTCTGGAATGGATTGGATACATTAAT CCTACCACTGGTTACACTGACTACAATCAGAAGTTCAAGGACAAGGCCACAT TGACTGCAGACAAATCCTCCAGCACAGCCTACATGCAACTGAGCAGCCTGAC ATCTGAGGACTCTGCAGTCTATTACTGTGCAACAGAGGGAGGTAATTGGGAG GACTACTGGGGCCAAGGCACCACTCTCACAGTCTCCTCA 72 ADWA15 CAGGTCCAACTGCAGCAGCCTGGGTCTGTGCTGGTGAGGCCTGGAGCTTCAG TGAAGTTGTCCTGCAAGGCTTCTGGCTACACCTTCACCAGCTCCTGGATGCA CTGGGCGAAGCAGAGGCCTGGACAAGGCCTTGAGTGGATTGGAGAGATTCAT CCTAATAGTGGTAATAGTATCTACAATGAGAAGTTCAAGGACAAGGCCACAC TGACTGTAGACACATCCTCCAGCACAGCCTACGTGGATCTCAGCAGCCTGAC ATCTGAGGACTCTGCGGTCTATTACTGTGCAAGATGGGGGGATTTTGACTAC TGGGGCCAAGGCACCACTCTCACAGTCTCCTCA 73 ADWA11 GAGGTTCAGCTGCAGCAGTCTGGGGCTGAGCTTGTGAGGCCTGGGGCCTTTG TCAAGTTGTCCTGCAAGGCTTCTGGCTTCAACATTAAAGACTACTATATGAA TTGGGTGTTGCAGAGGCCTGAACAGGGCCTGGAGTGGATTGGATGGATTGAT CCTGACAATGGTAATACTATATATGACCCGAAGTTCCAGGGCAAGGCCAGTA TAACAGCAGACACATCCTCCAACACAGCCTACCTGCAGCTCAGCAGCCTGAC ATCTGAGGACACTGCCGTCTATTACTGTGCTAGAAGACTACTTATGGACTAC TGGGGTCAAGGAACCTCAGTCACCGTCTCCTCA 74 ADWA10 GAGGTCCTGCTGCAACAGTCTGGACCTGAGCTGGTGAAGCCTGGGGCTTCAG TGAAGATACCCTGCAAGGCTTCTGGATACACATTCACTAACTACAACATGGA CTGGGTGAAGCAGAGCCATGGAAAGAGCCTTGAGTGGATTGGAGATATTAAT CCTAACAGTGGTGGTTCTGTCTACAACCAGAAGTTCAAGGGCAAGGCCACAT TGACTGTAGACAAGTCCTCCAGCACAGCCTACATGGAGCTCCGCAGCCTGAC ATCTGAGGACACTGCAGTCTATTACTGTGCAAGATGGGCCTACTATGGTGAA AGGTTTCACTACTTTGACTACTGGGGCCAAGGCACCACTCTCACAGTCTCCT CA 75 ADWA8 CAGGTCCAACTGCAGCAACCTGGGTCTGAGCTGGTGAGGCCTGGAGCTTCAG TGAAGCTGTCCTGCAAGGCTTCAGGCTACACATTCACCAGCTACTGGATGCA CTGGGTGAAGCAGAGGCCTGGACAAGGCCTTGAGTGGATTGGAAATATTTAT CCTGGTAGTGGTAGAACTAACTACGACGAGAAGTTCAAGAGCAAGGCCACAC TGACTGTAGACACATCCTCCAGCACAGCCTACATGCAACTCAGCAGCCTGAC ATCTGAGGACTCTGCGGTCTATTACTGTACAAGACCGCTCCAGTATAGGTAC GACGTCTATCCTATGGACTACTGGGGTCAAGGAACCTCAGTCACCGTCTCCT CA 76 ADWA8-1 CAGGTCCAACTGCAGCAACCTGGGTCTGAGCTGGTGAGGCCTGGAGCTTCAG TGAAGCTGTCCTGCAAGGCTTCAGGCTACACATTCACCAGCTACTGGATGCA CTGGGTGAAGCAGAGGCCTGGACAAGGCCTTGAGTGGATTGGAAATATTTAT CCTGGTAGTGGTAGAACTAACTACGACGAGAAGTTCAGGAGCAAGGCCACAC TGACTGTAGACACATCCTCCAGCACAGCCTACATGCAACTCAGCAGCCTGAC ATCTGAGGACTCTGCGGTCTATTACTGTACAAGACCGCTCCAGTATAGGTAC GACGTCTATCCTATGGACTACTGGGGTCAAGGAACCTCAGTCACCGTCTCCT CA 77 ADWA8-2 CAGGTCCAACTGCAGCAACCTGGGTCTGAGCTGGTGAGGCCTGGAGCTTCAA TGAAGCTGTCCTGCAAGGCTTCAGGCTACACATTCACCAGCTACTGGATGCA CTGGGTGAAGCAGAGGCCTGGACAAGGCCTTGAGTGGATTGGAAATATTTAT CCTGGTAGTGGTAGAACTAACTACGACGAGAAGTTCAAGAGCAAGGCCACAC TGACTGTAGACACATCCTCCAGCACAGCCTACATGCAACTCACCAGCCTGAC ATCTGAGGACTCTGCGGTCTATTACTGTACAAGACCGCTCCAGTATAGGTAC GACGTCTATCCTATGGACTACTGGGGTCAAGGAACCTCAGTCACCGTCTCCT CA 78 ADWA8-3 CAGGTCCAACTGCAGCAACCTGGGTCTGAGCTGGTGAGGCCTGGAGCTTCAG TGAAGCTGTCCTGCAAGGCTTCAGGCTACACATTCACCAGCTACTGGATGCA CTGGGTGAAGCAGAAGCCTGGACAAGGCCTTGAGTGGATTGGAAATATTTAT CCTGGTAGTGGTAGAACTAACTACGACGAGAAGTTCAAGAGCAAGGCCACAC TGACTGTAGACACATCCTCCAGCACAGCCTACATGCAACTCACCAGCCTGAC ATCTGAGGACTCTGCGGTCTATTACTGTACAAGACCGCTCCAGTATAGGTAC GACGTCTATCCTATGGACTACTGGGGTCAAGGAACCTCAGTCACCGTCTCCT CA 79 ADWA20 GATGTGCAGCTTCAGGAGTCGGGACCTGGCCTGGTGAAACCTTCTCAGTCTC TGTCCCTCACCTGCACTGTCACTGGCTACTCAATCACCAGTGATTTTGCCTG GAGCTGGATCCGGCAGTTTCCAGGAAACAAACTGGAGTGGATGGGCTACATA AGCTACAGTGGTAGCACTGGCTACAACCCATCTCTCAAAAGTCGAATCTCTA TCACTCGAGACACATCCAAGAACCAGTTCTTCCTGCAGTTGAATTCTGTGAC TACTGAGGACACAGCCACATATTACTGTACAAGAAGGGGCCTCTACCACTGG GGGTTTCCTTACTGGGGCCAAGGGACTCTGGTCACTGTCTCTGCA 80 ADWA25 GAGGTGCAGCTGGTGGAGTCTGGGGGAGACTTAGTGAAGCCTGGAGGGTCCC TGAAACTCTCCTGTGCAGCCTCTGGATTCACTTTCAGTAGCTATGGCATGTC TTGGGTTCGCCAGACTCCAGACAAGAGGCTGGAGTGGGTCGCAACCATTAGT GGTGGTGGTAGTTACACCTACTATCCAGACAGTGTGAAGGGGCGATTCACCA TCTCCAGACACAATGCCAAGAACACCCTGTACCTGCAAATGAGCAGTCTGAA GTCTGAGGACACAGCCATGTATTACTGTGCAAGCGACCCCTATTACTACGGT AGAAGGGACCTGGCCTGGATTGCTTACTGGGGCCAAGGGACTCTGGTCACTG TCTCTGCA V_(L) SEQUENCES-NUCLEIC ACIDS 81 ADWA2 GATATCCAGATGACACAGACTACATCCTCCCTGTCTGCCTCTCTGGGAGACA ADWA13 GAGTCACCATCAGTTGCAGGGCAAGTCAGGATATTAGCAATTATTTAAACTG ADWA16 GTATCAGCAGAAACCAGATGGAACTGTTAAACTCCTGATCTATTACACATCT AGATTATACTCAGGAGTCCCATCAAGGTTCAGTGGCAGTGGGTCTGGGACAG ATTATTCTCTCACCATCAGCAACCTGGAACCTAAAGATATTGCCACTTACTA TTGTCAGCAGTTTAGTGAGCTTCCTCGGACGTTCGGTGGAGGCACCAAGCTG GAAATCAAA 82 ADWA15 GATGTCCAGATGACACAGACTACATCCTCCCTGTCTGCCTCTCTGGGAGACA GAGTCACCATCAGTTGTAGGGCAAGTCAGGATATTAGCAATTATTTAAACTG GTATCAGCAGAAACCAGATGGAACTGTTAAACTCCTGATCTACTACACATCA CGATTACACTCAGGAGTCCCATCAAGGTTCAGTGGCAGTGGGTCTGGGACAG ATTTTTCTCTCACCATCAGCAACCTGGAACCTGAAGATATTGCCACTTACTA TTGTCAGCAATACAATAAGGTTCCGCTCACGTTCGGTGGTGGGACCAAGCTG GAGCTGAAA 83 ADWA11 GATATTGTGATGACTCAGGCTGCACCCTCTGTACCTGTCACTCCTGGAGAGT CAGTTTCCATCTCCTGCAGGTCTACTAAGAGTCTTCTGCATTTTAATGGCAA CACTTACTTGTTTTGGTTCCTGCAGAGGCCAGGCCAGTCTCCTCAGCGCCTG ATATATTATATGTCCAACCTTGCCTCAGGAGTCCCAGACAGGTTCAGTGGCA GAGGGTCAGGAACTGATTTCACACTGAGAATCAGTAGAGTGGAGGCTGAGGA TGTGGGTGTTTATTACTGTATGCAAAGTCTAGAATATCCATTCACGTTCGGC ACGGGGACAAAATTGGAAATAAAA 84 ADWA10 AGGTCACAATGACTTGCAGGGCCAGTTCAAGTGTAAGTTACATGCACTGGTA CCAGCAGAAGTCAGGATCCTCCCCCAAACCCTGGATTTATGCCACATCCAAC CTGGCTTCTGGAGTCCCTGCTCGCTTCAGTGGCAGTGGGTCTGGGACCTCTT ACTCTCTCACAATCAGCAGAGTGGAGGCTGAAGATGCTGCCACTTATTACTG CCAGCAGTGGAGTAGTAACCCACCCACGTTCGGAGGGGGGACCAAGCTGGAA ATAAAA 85 ADWA8 GACATCCAGATGACTCAGTCTCCAGCTTCCCTGTCTGCATCTGTGGGAGAAA CTGTCACCATCACATGTCGAGCAAGTGAGAATATTGACAGTTATTTAGCATG GTATCAGCAGAAACAGGGAAAATCTCCTCAGCTCCTGGTCTATGCTGCAACA CTCTTACCAGATGGTGTGCCATCAAGGTTCAGTGGCAGTGGATCAGGCACAC AGTATTCTCTCAAGATCAACAGCCTGCAGTCTGAAGATGTTGCGAGATATTA CTGTCAACATTATTATAATACTCCGTGGACGTTCGGTGGAGGCACCAAGCTG GAAATCAAA 86 ADWA20 GACATTGTGATGACCCAGTCTCACAAATTCATGTCCACATCAGTGGGAGACA GGGTCAGCATCACCTGCAAGGCCAGTCAGGATGTGAGTAGTGCTGTAGCCTG GTATCAACAAAAACCAGGGCAATCTCCTAAACTCCTGATTTACTGGGCATCC ACCCGGCACACTGGAGTCCCTGATCGCTTCACAGGCAGTGGATCTGGGACAG ATTATACTCTCACCGTCAGCAATGTGCAGGCTGAAGACCTGGCACTTTATTA CTGTCAGCAACATTATATCACTCCTTACACGTTCGGAGGGGGGACCAAGCTG GAAATAAAA 87 ADWA25 GACATTGTGATGACCCAGTCTCAAAAATTCATGTCCACATCAGTAGGAGACA GGGTCAGCGTCACCTGCAAGGCCAGTCAGAATGTGGGTACTAATGTAGCCTG GTATCAACAGAAACCAGGGCAATCTCCTAAAGCACTGATTTACTCGGCATCC TACCGGTACAGTGGAGTCCCTGATCGCTTCACAGGCAGTGGATCTGGGACAG ATTTCACTCTCACCATCAGCAATGTGCAGTCTGAAGACTTGGCAGAGTATTT CTGTCAGCAATATAACAGCTATCCGTACACGTTCGGAGGGGGGACCAAGCTG GAAATAAAA

The above examples are provided to illustrate the invention but not to limit its scope. Other variants of the invention will be readily apparent to one of ordinary skill in the art and are encompassed by the appended claims. All publications, databases, internet sources, patents, patent applications, and accession numbers cited herein are hereby incorporated by reference in their entireties for all purposes. 

1. An isolated antibody that specifically binds to human integrin β8 and inhibits adhesion of latency associated peptide (LAP) to αvβ8.
 2. isolated antibody of claim 1, wherein the antibody cross-reacts with mouse integrin β8.
 3. The isolated antibody of claim 1, wherein the antibody blocks TGFβ activation.
 4. The isolated antibody of claim 1, wherein the antibody antagonizes binding of LAP to αvβ8 with an IC50 below 5 nM.
 5. The antibody of claim 1, wherein the antibody competes for binding with an antibody selected from the group consisting of ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20.
 6. The antibody of claim 1, wherein the antibody comprises the complementarity determining regions (CDR1, CDR2, and CDR3) of the heavy and light chain variable regions of an antibody selected from the group consisting of ADWA-2, ADWA-8, ADWA-10, ADWA-11, ADWA-13, ADWA-15, ADWA-16, ADWA-25, and ADWA-20.
 7. The antibody of claim 1, wherein the antibody comprises the complementarity determining regions (CDR1, CDR2, and CDR3) of the heavy and light chain variable region sequences selected from the group consisting of: SEQ ID NO:1 and SEQ ID NO:16, respectively; SEQ ID NO:2 and SEQ ID NO:16, respectively; SEQ ID NO:3 and SEQ ID NO:16, respectively; SEQ ID NO:4 and SEQ ID NO:16, respectively; SEQ ID NO:5 and SEQ ID NO:16, respectively; SEQ ID NO:6 and SEQ ID NO:16, respectively; SEQ ID NO:7 and SEQ ID NO:17, respectively; SEQ ID NO:8 and SEQ ID NO:18, respectively; SEQ ID NO:9 and SEQ ID NO:19, respectively; SEQ ID NO:10 and SEQ ID NO:20, respectively; SEQ ID NO:11 and SEQ ID NO:20, respectively; SEQ ID NO:12 and SEQ ID NO:20, respectively; SEQ ID NO:13 and SEQ ID NO:20, respectively; SEQ ID NO:14 and SEQ ID NO:21, respectively; and SEQ ID NO:15 and SEQ ID NO:22, respectively.
 8. The antibody of claim 1, wherein the antibody comprises one or more human framework regions.
 9. A pharmaceutical composition comprising the antibody of claim
 1. 10. An isolated nucleic acid encoding the antibody of claim
 1. 11. An expression vector comprising the nucleic acid of claim
 10. 12. An isolated host cell comprising the vector of claim
 11. 13. A method of reducing TGFβ activation in a human in need thereof, the method comprising administering a sufficient amount of the antibody of claim 1 to the human, thereby reducing TGFβ activation in the human.
 14. The method of claim 13, wherein the human has a disease selected from the group consisting of asthma, multiple sclerosis or acute lung injury and at least one symptom of the disease is ameliorated by the reduced TGFβ activation.
 15. The method of claim 13, wherein the human has a disease selected from the group consisting of rheumatoid arthritis, psoriasis and chronic obstructive pulmonary disease and at least one symptom of the disease is ameliorated by the reduced TGFβ activation.
 16. A method of detecting the presence or quantity of integrin β8 in a biological sample, the method comprising contacting the biological sample with the antibody of claim 1 and detecting the presence, absence, or quantity of the antibody specifically bound to β8 in the sample.
 17. The method of claim 16, wherein the antibody is linked to a detectable label.
 18. The method of claim 17, wherein the label is fluorescent. 